Machine tool



*May 8, 1.945 D. MONTGOMERY ET AL 2,375,734

MGHINE TooL Filed March 4, 1940 5, Sheets-Sheet 2 INVENTORS A DONALD H.M0/V7'60Mf'/?Y\ May '8, 1945. D. H. MobrrGoMERY` ETA).

"MACHINE TooL Filed March 4, 1940 v 3 sheets-sheet s i TTORNEYS`mechanism for a collet or substanuauy Patented May 8, 1945 UNI-TEDySTATES s PATEN TiN oFFrcE MACHINE i'rooL Donald H. Montgomery,

West Hartford, and

Arthur H. Jobert, New Britain, Conn., assignors to The NewBritainMachine Company, New Britain, Conn., a corporation of ConnecticutApplication `Marchfl, 1940, Serial No. 322,124

`Our invention relates to a machine tool, and this application is acontinuation in part of our application, Serial No. 138,282, filed April22, 1937, now Patent No. 2,192,198, granted March `5, 1940.

It is the general object of our invention to provide various improvedfeatures connected with or related to the chucking means for barstock orWork pieces.

A more specific object is to "provide improved collet or chuck adjustingmeans and which, is l readily accessible for quick adjustment.

l Another object is to provide chuck or collet adjusting means, togetherwith 'means for automatically preventing accidental or intentionalspindle actuation during adjustment. Another object is y to providecompensating chuck, which will permit satisfactory chucking of `workpieces of substantially different sizes and which may be readily appliedand removed without substantial dismantling operations. l Another objectis to'provide improved means ys claims. (o1. 279-1) illustrating themodied collet adjusting means of Fig. 8. v V

Themachine in general will be referred to but briefly herein, areferencebeing made to our aforesaidapplication for a fuller disclosure of themachine in general and its operation.

`The spindle carrier 'l carries a plurality of pindles 2|5, for examplein, bearings 2|6-'2I1. Collets 2| 8 of conventionalor desired form areprovided for each spindle. The stock feed tube 2|9 having feed fingers22| for feeding thebar of for very readily removing a collet or chuckingl means from a spindle. Other objects and various features ofnovelty andinvention will be hereinafter pointed out or Will become apparent upon astudy of the illus- 4trated` disclosure of the invention.

Fig. 4 `is an enlarged fragmentary view `of the" collet adjusting andlocking mechanism; l

Fig. 5 is a fragmentary end View in elevation of `collet compensatingmechanism;

Fig. 6 is `an enlarged, partly sectional view of the compensatingmechanism shown in Fig. 5 and other associated parts;

Fig. is a fragmentary sectional view taken substantially in the plane ofmanner-i of Fig. 8 and illustrating the collet adjusting mech anism;` l

Fig. 8 is a fragmentary side View in partial section of one spindle andcollet adjusting means of a slightly modified form;

Fig. 9 is a fragmentary, enlarged sectional view preferred forms of theinvention l stock` is actuated in any usual manner forming no part 4ofthe present invention. The collet is secured to the collet tube 220 sothat when the latter is drawn rearwardly the stock is chucked up andIwhen moved orwardly the stock is released in the usual' manner. e

. While `the chucking means may takevarious forms, we `have disclosedacollet actuator broadly like that disclosed in` Montgomery patent,`No.2,153,971, April 1l, 1939. lThere is a sleeve 291 (Fig. 2) keyedatg298to the spindle 2|5. The sleeve carries an abutmentring 299, and wedgemembersinthe form of balls or rollers 300 are interposedbetweenrelatively inclined abutment surfaces on' the ring 299 and thesleeve 291. The

ment member or nut 303 on the collettube 220 1s` sleeve 297 fslidablycarries a chucking sleeve"30l having a bell mouth to camV the balls orrollers300 inwardly for forcing the abutment' 299 'rear- Wardly fordrawing the collet tube rearwardlyv andchucking up the bar stock. The'chucking sleeve3l| hasthe usual spool or'circumferential groove 302 forthe reception of a chucking fork,

as will be understood.

Between the abutment 299 and a second abutinterposed an improved`compensating mechae nism `designated generally 304 `to providecompensation for bar stock `varying somewhat `in size.` The abutment nut303 is screw threaded to the end of the collet tube and a lock `nut 305is also screw threaded on the collet tube and serves to lock up theabutment 303. `As shown in the drawings, the nut 305 has `a flange 306loverstanding a part of the vabutment nut 303. 'Il'he sleeve 306 isprovided with a slot 301 following the pitch of the thread onthe collettube and the abutment nut 303 carries a pin 308 fitting within the slot30'! fora purpose which will be described.

Each ofthe nuts 303-305are provided peripherally with gear teeth 30S-3H)for the purpose 0f rotating the' nuts by gear means which may beactuated from a conveniently located accessible remote point for colletadjustment or removal `and replacement. As shown more particularly in lthe bracket 3| I. The bracket 311 has a bearing for the shaft 314mounted in the thrust bracket and the shaft also acts as a support. Theshaftl 314 carries a pinion `315 meshing with agear 315 carried on astub shaft on the bracket 311. The gear 316 during normal operation ofthe ma- Chine is positioned between ,theV gears 309-310, as shown moreparticularly in Fig. 2f. The shaft 314 extends rearwardly` and isprovided with a manual crank or handle 311 located in a convenientlyaccessible position.

When the handle 311 is drawn rearwardly, the gear 316 `meshes withthegear 310 on the lock nut 305. Rotation of the handle 3,11 in properdirection will cause the'lock nut 305 to be unscrewed so as to unlockthe nut 303 and sufficient' rotation of the handle 311 will cause thepin 308 in the abutment nut' 303 to engage one endof the slot 301 (Fig.4)A and further rotation of the handle 311wil1 then cause the lock nutto be unscrewed and the Apin 308 will drag the abutment nut 303 with itfor unscrewing the same. When the nut 303 has reached the desiredposition, the handlel 311 may be rotated in the opposite direction to`tum the lock not 305 relatively to the abutment nut 303 and cause thelook nut to again lock up the abutment nut 303. When it is desired tomove. the abutment nut 303l in the opposite direction the lock nut 305is first loosened, as heretofore described, and the handle 311 thenshifted to cause the gear 316 to mesh with the gear 309 on the abutmentnut 303 which may then` be rotated by rotation of the handle 311 andduringsuch rotation the-lock nut 310 will be dragged along by means ofthe pin 308 engaging the slot 301. When the abutment nut 303 is in thedesired position oil-adjust-v `ment, the handle 311 isagain shifted tocause engagement between the gears310, 310 and the lock nut rotated tolock up the abutment nut 303. It will be seenthat when it is desired toremove theV collet completely, the handle 311 may be shifted to unlockthe lock nut 305`v and continued rotation will unscrew both of the nuts303- 305 from the collet tube simultaneously and'if the nut 305 engagesthe thrust plate 12, the collet will be forced'out forwardly and whencompletely unscrewed from thev nuts, the collet tube may be drawn outthrough the forward end of the spindle. When a new collet is inserted,the handle 311 may be shifted to engage the gear 316 with the gear 309and the new collet screwed into the nuts. The slot 301 and pin 308 willalways serve to hold the two nuts 303-305 in position so as to prbvide acontinuous thread for initial. engagement with the threaded 'end of thecollet tube. It should be here statedthat the collet tube is providedwith a keyway for engagement with a key 318 carried by the sleeve 291.

The improved compensating mechanism (Figs. 2, 5, 6), designatedgenerally 304 and interposed between the abutment collar 299 and theabutment nut 303, preferably comprises a two-part annular ring 319carrying a plurality of headed pins 32,0 secured thereto. Between thehead"v 321 of each pin andthe ring: 319 are interposed ,a plurality ofcupped spring washers 322 and end abutment washers 323. 'Ihese springwashers when in place are under an initial tension, that is to say, theyare preloaded. The abutment nut 303 is provided with bores 324 for the`reception of the heads 321 of the pins 320 and such recesses or boresare deep enough to permit sufficient inward movements of the headsforfurther compression of the compensating washers 322 occasioned by colletadjustment. The abutment nut 303 may carry locating and guiding pins325engaging between the two halves of the two-part ring 319, as shownparticularly in Figs. 5 and 6. Each half of the ring 319 adjacent eachparting line carries a pin 326. One of the pins carries a spring latch321 while the opposite end of the latch engages over thev pin on theother section.

of the `ring 319. A tang 328 extendsfrom each latch to such an extentthat a screw driver or similar instrument may be inserted between thetang and thecompensating washers for releasing the latch 321V andpermitting separation of the two ring halves. `Ir for any reasontheoompensator should become damaged or if a compensator havingdifferent characteristics isnrequired, the nuts 303- 305 may bebackedoilithe chucking sleeve 301 moved to the right as viewed in Fig.2,' and the two halves of the compensating ring 319 separated andremoved froml the spindle laterally; that is to say, the entire spindleassembly need not be dismantled for the purpose of changingcompensators, and yet compensators may be very readily removed andreplaced and when in place Will besecurely held not only by` thespring'latch clamps 32'1'b`u`t by` the pins 325 and the engagement ofthe heads 321 of the pins in) therecesses orpbores 324 of the abutmentnut a 3l, v

In that form of the invention shown'in Figs. 7, 8 and 9, the generalmachine parts are the same as those heretofore described and havebeengiven the same reference characters. However, Ainthe [form shown inthese latter gures, instead of` having a lock nut for the chuckingabutment, we have provided improved means toavoid the use of such locknut. As illustrated, the chucking tube 220 is provided'with threads ofpeculiar form. The thread has one side 400 extending at a relativelysmall angle to the axis of the spindle Such'angle may vary somewhat butis preferably of the order Aof 12. The opposite side 401 vof the threadextendsl at a relatively sharp angle tothe aXis of the spindle and inthe preferred y:form

extends at about right angles to the thread face l 400. When thechucking tube 220 is so arranged as to be drawn toward the left in Fig.9, the threads taper outwardly and rearwardly,V vas shown.` However,should the chucking tube be arranged to chuck up when moved in theopposite direction, that is, toward the right', the threads would bereversed. The interengaging threads 402 on the chucking abutment 403Acorrespond in form to the threads on the-chucking tube and the fit Vofthe threads between `the chucking tube and chucking abutmentispreferably a relatively loose one so that when the chucking abutment 403is drawn toward theleft, the in` clined faces of the threads ride up oneach other with a very'tight frictional grip. The relatively low angleof inclination of` the threads is such that the tight binding of thechucking abutment and chucking tube will notlbe` disturbed during allordinary chucking and unc-bucking operations. When it becomes necessaryto loosen the grip off-the `chucking abutment 403 on. the lchucking tube220, as when adjusting the chucking abutment on the tube, or when it isdesired to remove the chucking tube completely, it is` necessary toforcibly rotate the abutment 403 and preferably to break the grip bymeans of asudden jar. With that end in View, tl'ie shaft 3 I4 and therelatively heavy fly` wheel type handle or manual member may be coupledtogether by means of a lost motion connectiomfor example, the hubl ofthe. ily Wheelhandle 311 may be provided with a slot 404 and a pin 405`may be secured to the shaft. It will be understood, o f course, that inthis case the hub is rotatable on the shaft `3H! so that when it isdesired tc break the tight grip of the chucking abutment on the`chucking tube, the handle is quickly rotated and `when r the pin 405 isengaged by the end of the slot in the wheel hub, avery substantial jaris imparted to the chucking abutment, the` grip is broken, andtherelatively loose fit between the threads then permits very easy rotationof the chucking abutment so that it may |be readily adjusted or mayberotated to a degree `sufficient to force the chucking tube and colletoutwardly of the spindle. e When the chucking tube has been Iremovedfrom the spindle it Willbe `seen that the chucking abutment of Fig.` 9,as well as` the chucking abutment and lock nut'of the first form of theinvention, will be concentrically supported by machine parts so as to bein a position to again receive `the chucking tube when put into y place.

'In order to prevent accidental engagement of the `adjusting means whenthe chucking means is movedlto the chuck closed position, we may providea safety abutment 406 which may be carried by the `chucking slide sothat when the latter is` moved toward the left (Fig. 8) in moving the lchucking means of the chuck to closed position, the safety abutment 406Will engage one of the actuating gears and hold it in its inoperae tiveposition as shown in Fig. 8,

Instead of the compensating mechanism of the v first form of `theinvention, the resilient means of the chucking mechanism may comprise adisklike spring washer 401 as shown.

and means for detachably securing Asaid ring-like members together,whereby the latter may be detached from each other and removed from saidspindle in a lateral direction.

2. In a machineof the character indicated, a

frame, a rotatable spindle supported therefrom, a collet tube in saidspindle, chucking abutment means threaded to said collet tube, saidchuck ing abutment means including an abutment member and a lock nutmember, each ofsaid members having gear means associated therewith andspaced apart longitudinally of said collet tube, an actuating gearmovable` into coacting engagement with the gears of said abutment andsaid lock nut, and anactuating shaft and handle for said actuating gearlocated at a point remote from'said chucking `abutment means,.`f'or thepurpose described,

3. In a machine of the character indicated, a

frame, a spindle carried there-by, a chuck actu `atcr in said spindle,means for actuating said chuck actuator,.including a chucking abutmentand a lock nut therefor, said abutment and lock nut being screwthreadedto one of said members, and means for coupling said chucking abute mentand lock nut to each other so as to permit only limited relativerotation between said chucking abutment and lock nut, for the purposeset forth. f

i DONALD H. MONTGOMERY. l ARTHUR H. JOBERT.

